Theory Of Operation - Lincoln Electric COMMANDER 400 SVM133-B Service Manual

E-2
FIGURE E.2 – BATTERY, STARTER, ENGINE, ROTOR AND STATOR
STARTER
ALTERNATOR
ENGINE
SHUTDOWN
SOLENOID
IDLER
SOLENOID
BATTERY
ENGINE
SENSORS
GENERAL DESCRIPTION
The Commander 400 is a diesel engine driven welding
power source. The machine uses a brushless asyn-
chronous alternating current generator for DC stick
electrode welding and for 120/240 VAC auxiliary stand-
by power. As a generator it can supply up to 10,000
watts of 120/240 volt AC power. As a welder it provides
up to 400 amps of DC constant current output in six
slope-controlled ranges. In addition a seventh general
purpose welding range provides up to 575 amps of
constant current welding output.
The stick and wire model has a CV terminal for con-
stant voltage wire welding.
BATTERY, STARTER, ENGINE,
ROTOR AND STATOR
The 12VDC battery powers the engine starter motor
and supplies power to the main control board for the
engine protection circuitry.
supplies "charging" current for the battery circuit. The
battery circuit also provides power through the main
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

THEORY OF OPERATION

MECHANICAL
ROTOR
ROTATION
EXCITER
WINDINGS
115VAC
EXCITER
14 PIN
CAPACITORS
AMPHENOL
115/230VAC
BY-PASS
RECEPTACLE
PC
6 PIN BOARD
AMPHENOL
EXCITER VOLTAGE
FEEDBACK
BOARD
The engine's alternator
COMMANDER 400
SCR/DIODE
OUTPUT
OUTPUT
CHOKE
BRIDGE
SCR GATE SIGNALS
42VAC
REMOTE
SWITCH
FINE
OUTPUT
CONTROL
12VDC
control board for the idler solenoid, which is mechani-
cally coupled to the engine's throttle linkage.
The diesel engine is coupled to a brushless asynchro-
nous three-phase alternating current induction genera-
tor. See Induction Generators. The excitation or
"flashing" voltage is developed in the exciter windings
and capacitor configuration. The rotor, which is manu-
factured by casting aluminum through steel lamination,
is mechanically coupled to the engine. Through exci-
tation of this rotating magnet, voltages are produced in
the stationary windings of the stator. There are three
separate and isolated sets of windings incorporated in
the stator lamination. Each set has a different number
of turns producing different magnitudes of AC output
voltages. These three windings are the three-phase
weld winding, the three-phase exciter winding; which is
tapped for single phase auxiliary standby power; and
the 42VAC single-phase winding, which supplies power
to the main control board.
The engine protection circuit shuts the engine off in the
event of low oil pressure, engine over temperature,
malfunction in the engine's alternator system, or a low
fuel condition.
E-2
NEGATIVE
TERMINAL
CV
TERMINAL
SHUNT
POSITIVE
TERMINAL
F
E
FEEDBACK
E
D
B
A
C
K
CV
BOARD
METER
MAIN
CONTROL
BOARD
ENGINE
PROTECTION
BOARD
CURRENT/ MODE
SELECTOR
SWITCH